Here’s a simple script to add a random string to a SQL Update:
update <dbname>
set <field> = (SELECT SUBSTRING(CONVERT(VARCHAR(40), NEWID()),0,9))
This will update each row with a distinct 8 alphanumeric characters, e.g. C2552926
Breaking this down in terms of functionality:
NEWID() – generates a UUID
VARCHAR(40) – tells CONVERT() what string data type, max len 40
CONVERT() – takes the UUID and converts it to a string .
SUBSTRING(...0,9) – takes the value of CONVERT and takes from position 0-9, leaving 8 chars. In this case, we only want the first 8 chars because the 9th is a dash). There’s nothing wrong with adding the dash,
Changing 9 to 50 leaves us this:
11632BF8-EE3C-40CF-9C29-DECC6808C874
If you need to make a complex password in T-SQL, check out this post.